Falling accidentally is a serious safety concern, especially if the person is old or alone. For example, a person may stumble or trip and fall from an upright position to a ground while walking. A person may also lose his/her balance and fall from a chair to a low ground. In some situations, the person may be elderly, alone, or for some reason, not receiving help from other people. It is, therefore, desirable to have fall detectors that detect such fall accidents and make sure that the person receives help.
Some conventional technologies for solving the above-mentioned problem include video monitoring and acoustic vibration monitoring. However, video monitoring requires installation of expensive apparatus and has a high false detection rate, and acoustic vibration monitoring is usually implemented indoor, therefor is limited in area coverage.